JBL L20T Review

TABLE OF CONTENTS

MY STORY WITH JBL L20T

I was searching for a small set of speakers for my bedroom and came across these JBL L20T monitors. A quick Internet search revealed mostly positive opinions and because I really enjoyed listening to JBL L26 and L100, I thought I would give JBL L20T a go. The speakers, apart from a couple of scuffs here and there, turned out to be in very good condition.

Please note – usually before reviewing vintage speakers, I recap the crossovers to ensure that capacitors are within manufacturer’s specification. On this occasion, caps were within the specs, so there was no need to replace them. Also, bear in mind that purchasing vintage speakers is always a gamble. 30 and often 50 years it’s a long time, and one can never be sure how this time affected the loudspeaker drivers. Consequently, it is possible that the JBL L20T that you have purchased will measure and sound different than the pair I reviewed. As a matter of fact, I’ve learnt long after this review was conducted, that the 035Ti tweeter used in this speakers gets peaky over time. Apparently this is a result of the foam pad behind the tweeter diaphragm disintegrating over time and loosing its dampening properties. There are reform kits you can get online to restore these tweeters to factory specification. I’m afraid though, I did not know about any of this at the time when I was reviewing these speakers.

SPEAKER INFO

Model History

Following the success of JBL’s L Series from 1970s, JBL decided to release another L Series in the mid-80s. As previously, the whole series was a domestic version of JBL’s studio monitors from that era, and included the following models: L20T, L60T, L80T and L100T. The studio equivalent of the reviewed speakers were the JBL 4406 – nearfield studio monitors.

Design

The JBL L20T’s were a compact two way bookshelf speaker, that according to JBL, are supposed to offer extended frequency response, great dynamic range and reproduction of the full sound stage. They feature JBL’s acclaimed titanium high frequency transducer, O35Ti, capable of producing frequencies way above the audible frequency range. Considering their size, they offer extremely high power handling, which combined with their average sensitivity of 87dB, means that they can be played fairly loud.
 

JBL L20T Specs

LOOK & FEEL OF JBL L20T SPEAKERS

The finishing quality is very good. The enclosures are made of chipboard, finished in a real wood veneer and dampened with open cell foam. Quite rigid and relatively heavy considering the size.
The drivers are very neat and remind me a bit of the units from Yamaha NS-1000s – very industrial and solid. The tweeters feature domes made from titanium, whereas the bass drivers feature cones made from polypropylene, suspended on rubber surrounds. These are driven by relatively hefty ferrite magnets, mounted on the back of rigid cast alloy baskets. The crossovers are pretty standard and feature fairly decent components, especially in comparison to JBL crossover’s from the 70s.

SOUND OF JBL L20T

First Impressions

Having experienced and being impressed by older JBL monitors, I had really great hopes for these JBL L20T bookshelf speakers. When I plugged them in for the first time, they very much reminded me of my laptop speakers (i.e. peaky treble). They just sounded a little too bright for my taste. I was hoping that this feeling will go away as I spend more time listening to the speakers.

Bass

For their relatively small size, JBL L20T are capable of playing quite loud without any audible signs of distortion, which can make songs such as The Flat Earth by Thomas Dolby enjoyable when played loud. The attack is pretty good and the drums can sound quite dynamic, albeit not very realistic in terms of tone. The speakers go quite low for the size, however, because of the amount of treble they generate in relation to bass, they sound quite thin. This is very noticeable on recordings with pianos and double bass. Unfortunately, regardless of how many attempts I made, this leanness did not go away, and I constantly felt a lack of something in bass.

Midrange, Treble and Soundstage

The midrange and treble do not seem to be well balanced. Clapping sounds more like rain, and this is very noticeable on live recordings such 4 Jezdzcy by Kult from their MTV Unplugged album. I also did not enjoy the woodwind instruments on the JBL L20T – instead of soulful and enjoyable experience that I usually have with Ben Webster’s My Romance album, I received fairly cold and not a very engaging one. Furthermore, the speakers give an impression of a relatively small sound stage – this is especially noticeable, when I compare them directly with my Yamaha NS-1000. When I switch from Yamaha’s to JBLs, everything becomes smaller and shallower. This means that instead of creating an illusion that I am at a concert, they just sound like a set of speakers. The vocals and guitars tend to sound OK, but nothing to write home about.

Overall, and despite trying very hard, I struggled to find anything that I would like about these speakers. Which is interesting, as I have seen plenty of positive comments about them on various forums. Have a look at the ‘Please note’ section in the MY STORY WITH JBL L20T paragraph, as this may shed some light on these difference.

CONCLUSION

The JBL L20T in their original vintage condition are not very enjoyable and not very engaging to listen to. Thin and relatively cold sounding. Good attack for the size and impressive power handling. If you are considering a pair, you’ll need to explore what would be required to bring them back to manufacture’s specification, as this is likely to fix most of the shortcomings I experienced.

Balance of Sound:
Neutrality of Tone:
Transparency:
Soundstage:
Attack:
Engagement:
Total Score:

SONGS MENTIONED IN THIS REVIEW

Kult – 4 Jezdzcy (MTV Unplugged)
Thomas Dolby – The Flat Earth
 

Reviewed: November 2016 | Published: December 2016